1. Field of the Invention
The present invention relates to a device having an imaging function, and in particular, the present invention relates to a digital device having an image capturing function to capture an image of an object utilizing an imaging element such as a television telephone, a surveillance camera, a drive recorder, and the like, for example.
2. Description of Related Art
In a device having an imaging function such as a television telephone, it is required to restrict displaying of a specific photographed image in order to protect security or privacy. To fulfill this requirement, a television telephone which employs a structure that closes a camera cover to prevent input of an image when a prescribed condition is not fulfilled, has been proposed in JP-A-H08-032945. However by this structure the television telephone can not deal with a case where there is a part not to display in one part of a photographed screen. For example, it cannot perform a display of photographed image with covering only clothes of a speaker or only background of the speaker.
The above described problem can be solved by employing a structure which converts an area other than a part of a face of the speaker to a prescribed covering information to display such as a television telephone that has been proposed in JP-A-S63-142986. In the television telephone disclosed in JP-A-S63-142986, a structure is employed in which the part not to display is covered by focusing on that a variation of mouth movement is larger than a variation of eye movement, designating coordinates of a predetermined above and below and right and left area of coordinates of a mouth position as a reference point and inputting an image signal of bright neutral color to coordinates other than the area. Further in JP-A-S63-142986, a structure is also disclosed in which a speaker designates an area to be covered by manual operation while the speaker sees the picture screen.
However, in the television telephone disclosed in JP-A-S63-142986, because it is necessary to detect the mouth position, there is a possibility that the part not to display in the photographed screen is displayed, when the speaker changes direction of his/her face or the speaker leaves from the television telephone. These problems can be solved in a certain extent by that the speaker designates the part to be covered with a manual control. However, it cannot deal with a case where the television telephone is abruptly moved. That is to say, if a position of the photographed screen is shifted by change of position of the television telephone, the part not to display comes off from the covered area and it is displayed. At any rate, by the television telephone disclosed in JP-A-S63-142986, change of relative position of the object with respect to the photographed screen cannot be detected, as a result, there is always a possibility that the part not to display in the photographed screen is displayed.